Toa Electronics P-912MK2 User Manual

Operating Instructions

TOA 900 SERIES II

POWER AMPLIFIER

P-906MK2 P-912MK2 P-924MK2

P-906MK2 P-912MK2

P-924MK2

THE LIGHTNING FLASH WITH ARROWHEAD WITHIN A TRIANGLE IS

INTENDED TO TELL THE USER THAT PARTS INSIDE THE PRODUCT ARE A RISK OF ELECTRIC SHOCK TO PERSONS.

TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER.

NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED

SERVICE PERSONNEL.

Please follow the instructions in this manual to obtain the optimum results from this unit.

We also recommend that you keep this manual handy for future reference.

THE EXCLAMATION POINT WITHIN A TRIANGLE IS INTENDED TO TELL THE USER THAT IMPORTANT OPERATING AND SERVICING

INSTRUCTIONS ARE IN THE PAPERS

WITH THE APPLIANCE.

TOA Corporation

Contents

General description

Features

Nomenclature

Front panel

Rear panel

Input connections Output connections Rack mounting

Operation

Volume adjustment

Installation Servicing Specifications

Appearance (P-906MK2/P-912MK2) Appearance (P-924MK2)

2 2

General Description

The TOA P-906MK2, P-912MK2 and P-924MK2 Power Amplifiers deliver up to 60 watts, 120 watts and 240

watts of power respectively at less than 0.5% total harmonic distortion (THD) from 20 to 20,000 Hz

(transformerless 4-ohm output). The power amplifiers have a high-impedance direct input and an input port

(edge connector) to accept one plug-in module. Module selection is determined by application among the

TOA plug-in modules.

The power amplifiers have a low-cut switch for a cutoff frequency of 60 Hz, and an input-level switch for input

sensitivity of 1V (0 dBV) or 100mV (–20 dBV). Output terminals provide connections for 4-ohm and 8-ohm speakers, plus 25-volt and 70-volt speaker distribution outlets. With plug-in modules, the power amplifiers

may be used as a PA amplifier.

The power amplifiers can be rack mounted by using optional rack mounting bracket MB-25B(P-906MK2,

P-912MK2) and MB-35B(P-924MK2). The optional perforated panel PF-511 provides suitable ventilation, finished in color to match the power amplifiers.

Features

1. Wide frequency response : 20 ~ 20,000 Hz ± 1 dB

2. Low distortion and noise level

3. Excellent output regulation

4. A full range of plug-in modules

5. Self-protecting circuitry design

6. Varied output impedances : 4 ohms, 8 ohms, 25 and 70 volts

7. Input level switch (selectable 1000 mV/100 mV)

8. Portable or rack mounting type

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Nomenclature

Front Panel

P-906MK2, P-912MK2

P-924MK2

Power Switch

Applies line power. Two-position push button

switch for on/off modes.

Power Indicator LED

Green LED lights when the power is switched

"ON".

Signal Indicator LED

Green LED lights when more than -30 dB signal

level is fed to the inputs by means of the master

volume control.

Normal Indicator LED

Yellow LED lights when fed to the proper signal

level.

Peak Indicator LED

Red LED lights when amplifier approaches

clipping level. If steady lit, the input level control

should be turned down until the LED flashes.

Protection Indicator LED

Remains lit for about 5 seconds after power

switch is turned ON.

Master Volume Control

Adjust gain of input.

– 3 –

Rear Panel

P-906MK2, P-912MK2

P-924MK2

AC Power Cord

Connects to power source.

AC Outlet (Unswitched)

Provides AC power for auxiliary equipment with

power consumption of up to 500W.

Impedance Select Switch

Selects the desired impedance.

Enables unbalanced output of low impedance

when this switch is set to "DIRECT".

Output terminals

Connect to speakers.

Module Input Port

Accepts optional PLUG-IN MODULES.

Application determines type of module.

For details, refer to Plug-in Module Instruction

Manual.

Low-Cut Switch

Cut off unnecessary low frequency.

Input Level Switch

Selects input sensitivity. Place in "1V" (0 dBV)

position when normally used as a power

amplifier.

Note: The position of INPUT-LEVEL SWITCH

should be changed according to modules

used or equipment connected to DIRECT

INPUT TERMINAL.

Direct Input Terminal

Connects directly to external equipment without

using modules. Unbalanced 10k ohms.

AC Fuse (250V, 7A)

DC Fuse (250V, 8A)

DC Fus e (250V, 8A)

Protects amplifier from excessive current drain.

Replace only with same type fuse.

Refer to qualified service personnel if fuse blows

repeatedly.

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